The present invention relates to article supports, such as shelves and table tops, and more particularly, to an article support that is generally spill-resistant and to a method for producing such an article support.
Article supports include shelves and table tops which may be used to support a variety of items. Conventionally, cabinets and appliances, such as hospital cabinets, kitchen cabinets and refrigerators, have multiple shelves for storing items, including liquids such as medicines, food, and beverages, vertically upright. Typically, such shelves extend between two interior upstanding appliance or cabinet walls, and are generally level. Tables, such as kitchen tables, have a table top which is a horizontal surface that can support a variety of items, including liquids such as food and beverages. Typically, such table tops are supported by three or more vertical legs to maintain them in a horizontal position, a suitable distance from the floor.
Article supports may be made of a tempered glass sheet surrounded by a plastic or metal frame. Items are placed on the top surface of the sheet portion of such article supports. When liquid spills on one of the article supports, it may not be confined to that article support and may overflow from the article support at its edges. The frame surrounding the sheet is often designed to limit this overflow, so that small spills can be trapped at the frame. However, even with small spills, liquid often leaks through the junctures between the sheet and the frame and spills to the shelf or floor below it. It is therefore desirable to prevent leaking of liquid from the top surface of such shelves at the juncture between the sheet and the frame, providing a shelf with improved spill resistance.
Framed article supports are typically manufactured either by pre-manufacturing a frame and dropping the glass in the frame (the xe2x80x9cdrop in glass methodxe2x80x9d) or by moulding a frame directly about a glass sheet (the xe2x80x9cencapsulation methodxe2x80x9d).
In the xe2x80x9cdrop in glass methodxe2x80x9d, the front, rear and side portions of a metal or plastic frame are first individually extruded from metal or plastic. These frame portions are then attached to form a frame, and a tempered glass sheet is slid freely into the frame to create the article support. As there is no chemical or mechanical bond between the top surface of the sheet and the frame, article supports made by this method are not very spill-resistant. Also, such frames lack integrity and often come apart, as the frame portions are attached together.
In the xe2x80x9cencapsulation methodxe2x80x9d, a tempered glass sheet is secured in a plastic injection mould. A hot melt of resin is then moulded around the edge of the glass and is permitted to cool to create the framed article support. As will be appreciated, the resin forms a tight bond with the glass sheet near its edges, by adhering to the glass. Although this may produce an article support that has increased spill-resistance, it does not permit easy removal of the glass from the frame to permit recycling of the frame and the glass, should the sheet or frame break. Moreover, this method requires an injection mould particularly suited to seat a glass sheet. Additionally, this method results in significant glass breakage, of up to approximately 30%, during the manufacturing process. As will be understood, this waste increases the overall production costs of such article supports, causes an occupational hazard, and raises environmental concerns. Finally, as the glass sheet is superheated at its perimeter and placed under extreme pressure during the injection moulding process, the resulting article support may be weak and prone to break, in use.
The present invention attempts to overcome some of the disadvantages associated with known article supports, and methods for producing such article supports.
It is an object of the present invention to provide an improved spill-resistant article support and method for producing such an article support.
In accordance with one aspect of the present invention there is provided a spill-resistant article support comprising a generally planar sheet having a flat top surface; a frame receiving said sheet, said frame comprising: first and second opposing side members each defining a lengthwise extending groove; said grooves receiving opposing edges of said planar sheet; said first and second side members each comprising a side lip; each said side lip covering a portion of said top surface; a front member, extending between said side members and in abutment with an end of said sheet; said front member comprising a front lip; said front lip covering a portion of said top surface; said side lips meeting said front lip such that said lips extend continuously along a periphery of said sheet; said frame comprised of heat sensitive material; said material adapted to expand at a first temperature so that said sheet is freely slidable within said grooves for easy removal of said sheet from said frame; said material further adapted to contract at a second temperature so that said edges of said sheet are tightly engaged within said grooves and said side and front lips tightly abut said top surface to inhibit spillage of liquids from said top surface at said periphery.
In accordance with another aspect of the present invention there is provided a method for producing a spill-resistant article support comprising the steps of: a. moulding a frame using heated plastic, said frame comprising first and second opposing side members each defining a lengthwise extending groove; said first and second members each comprising a side lip; said frame further comprising a front member, extending between said side members; said front member comprising a front lip; said side lips meeting said front lip such that said lips extend continuously along a perimeter of said frame; b. allowing said frame to partially cool and sufficiently harden to withstand insertion into said grooves of a planar sheet having a thickness less than that of said grooves; c. sliding said generally planar sheet into said grooves until an end of said sheet abuts said front member such that said frame receives edges of said planar sheet and said side and front lips cover a portion of said top surface; d. cooling said frame and said sheet, thereby permitting said frame to contract so that said edges of said sheet are tightly engaged within said grooves and said side and front lips tightly abut said top surface of said planar sheet.
In accordance with yet another aspect of the present invention there is provided a method of disassembling an article support, said article support comprising: a generally planar sheet; a frame receiving said sheet; said frame comprising first and second opposing members each defining a lengthwise extending groove; said grooves receiving opposing edges of said planar sheet; said edges of said sheet tightly engaged within said grooves of said frame; said frame made of a heat sensitive material and having a slot, comprising the steps of: a. heating said article support, so that said heat sensitive material expands so that said sheet is freely slidable within said grooves of said frame; b. removing said sheet from said frame through said slot.
The present invention provides a spill-resistant article support and a method for producing such an article support. As the method does not require superheating of the sheet and subjecting the sheet to high pressure, glass breakage may be minimized. The resulting article support maintains its integrity in the finished product. Also, should either the frame or sheet portion of the article support break, recycling of either element is permitted, as the sheet may be easily removed by warming the frame.